DESCRIPTION: (Applicant's Description) This project has two broad goals. The first is to develop CD-tagging technology into a robust tool for comprehensive analysis of the proteome of cultured cells, including primary tumor cells. The second is to develop discovery and analysis technologies that efficiently search CD-tagged cell libraries to identify and analyze genes and proteins that may have value in cancer diagnostics and therapeutics. Within this second goal we will focus on two areas: identifying cell surface receptors that trigger growth arrest or apoptosis, and identifying proteins whose levels rise in response to myc oncogene activation.